A series of earthquakes have devastated parts of Turkey and Syria, killing more than 3,000 people and toppling thousands of buildings.
The quakes, centred on Turkey’s south-eastern province of Kahramanmaras, were felt as far away as Cairo in Egypt and Beirut in Lebanon.
They hit a region that has been shaped on both sides of the border by more than a decade of civil war in Syria and the refugee crisis the conflict created.
The magnitude 7.8 earthquake that struck Turkey and Syria on Monday is likely to be one of the deadliest this decade, seismologists said.
The epicentre was about 16 miles (26 km) east of the Turkish city of Nurdagi on the East Anatolian Fault. The quake radiated towards the northeast, bringing devastation to central Turkey and Syria.
Eleven minutes after the initial quake, the region was hit by a 6.7-magnitude aftershock. A 7.5-magnitude quake came hours later, followed by another 6.0 spasm in the afternoon.
On average, there are fewer than 20 quakes over 7.0 magnitude in any year, making Monday’s event severe.
Why was it so severe?
The intersection of three tectonic plates
The region is one of the world’s most seismically active, meaning it is prone to earthquakes.
Earthquakes happen when massive blocks of the earth’s crust – or tectonic plates – suddenly move past each other.
The region of Turkey and Syria is at the intersection of three of these plates: the Anatolian, Arabian and African plates.
The Arabian plate is pushing northwards into Europe, causing the Anatolian plate to be pushed westward at a rate of about 2cm per year.
It’s this stress, that has been accumulating for decades, that has now been released with fatal consequences.
The East Anatolian Fault is a strike-slip fault. In those, solid rock plates are pushing up against each other across a vertical fault line, building stress until one finally slips in a horizontal motion, releasing a tremendous amount of strain that can trigger an earthquake.